mesa: turn on NV_conditional_render for software drivers

src/mesa/main/extensions.c

@@ -311,6 +311,7 @@ _mesa_enable_sw_extensions(GLcontext *ctx)
    ctx->Extensions.MESA_texture_array = GL_TRUE;
    ctx->Extensions.MESA_ycbcr_texture = GL_TRUE;
    ctx->Extensions.NV_blend_square = GL_TRUE;
+   ctx->Extensions.NV_conditional_render = GL_TRUE;
    /*ctx->Extensions.NV_light_max_exponent = GL_TRUE;*/
    ctx->Extensions.NV_point_sprite = GL_TRUE;
    ctx->Extensions.NV_texture_env_combine4 = GL_TRUE;